Wherever you look these days, there’s an app or game trying to nickel and dime you for every penny you have. They do this by offering up a smorgasbord of in-app purchases, which do everything from letting you skip levels, unlock additional content, or even allowing you play the game, in some extreme cases. For all the moaning and groaning every time a new title is launched with in-app purchases, you would think that in-app purchases are the worst thing ever to happen to apps and games.

But here’s the thing: not all in-app purchases are bad, and most of the time, I’m actually OK with them.

In-app purchases can be grouped into roughly two main kinds. The most popular seem to be the ones that unlock content (additional levels, chapters), or there are others that have a direct effect on gameplay (upgrades, hints, bonuses). Some apps also offer purely cosmetic enhancements, such as additional colour packs or sound effects. The official Pokédex app for iPhone pictured above lets you unlock Pokédex data for the various regions, and puzzle games with a built-in hint mechanic usually let you purchase an unlimited amount of hints for a once-off fee. I wouldn’t hesitate to buy every episode of The Walking Dead or every game in the Ace Attorney HD Trilogy, mostly because I know the games and have played them before, but those who are a little more cautious with their iTunes credit get the chance to try out the game before they take the plunge. If they like what they see, a once-off in-app purchase is right there.